Wednesday, August 7, 2013

Avian influenza: first transmission from person to person detected - Times Online

researchers have found new evidence that the H7N9 virus can jump from person to person. There is no need to panic: The pathogen is limited transferable


An infected with the new H7N9 virus girl in a hospital in Beijing

A with the new H7N9 virus-infected girl in a hospital in Beijing

There is the first medically documented case of transmission of avian influenza from person to person. Chinese scientists have made it public on Wednesday and confirmed with what is already suspected for some months. In April, the World Health Organization has reported that bird flu had spread in individual cases among close family members in China. Chinese scientists had previously doubted that birds are the only source of infection.

The new development was “worrying” and should be followed closely, the researchers wrote in the online journal BMJ . A reason to panic, but not to the scientists: The bird flu virus H7N9 has not yet been able to greatly spread between people, said epidemiologist Chang-jun Bao of health and prevention center of east China’s Jiangsu Province. It broadcasts primarily from birds to humans.


scientists had long feared that the virus could change so that it can be easily transmitted from person to person. In their new study, Chinese researchers described the situation of a 60-year-old man who died in hospital after he was infected with the virus. Apparently he put his 32-year-old daughter to it. The daughter, who had cared for over a week for her father also died in the hospital.

The woman had, the study found no contact with potentially infected poultry. Thus was the “most likely explanation” the contagion of her father, who had regularly visited poultry markets, according to the researchers. Genetic testing also showed that the viruses were virtually identical with father and daughter.

Flexible flu virus

flu viruses occur naturally present in different types and specialize in different hosts. People under immediate influenza virus each year trigger a flu that goes around the globe. In Germany alone each year hundreds of thousands to over a million people a real flu.

Which virus subtype dominates the flu is different from year to year. In the 2009/2010 season, it was the H1N1 example , who was known by the misleading name swine flu , because he once mutated in pigs and to a human human infectious form developed.

H and N proteins of the viral envelope hemagglutinin and neuraminidase be abbreviated, of which there are respectively different structures.

avian A/H5N1

insights into the still quite unexplored A/H7N9 virus, the scientists conclude largely from what they know about the better-known avian influenza A/H5N1. Since 2003 she is always sporadically among men has occurred, especially in Egypt, Indonesia and Vietnam – and nearly always in the regions where people in close contact with infected poultry live animals for slaughtering and processing the meat itself. So far 37 people died in the new A/H7N9-Virus according to the World Health Organization, 132 have become infected.

The WHO has so far cost the A/H5N1-Virus 377 human lives worldwide. These pathogens but also is still mainly a problem for poultry farmers and it solves no real epidemics among people. He remains an animal disease , people concerned only in exceptional cases.

The possibility of viral transmission from human to human is still limited: None of the other 43 people who are in close contact with the two patients had, including hospital staff, put on, according to the scientists. One explanation could be that there may be a genetic predisposition to infection. The seriously ill daughter could no longer be questioned. Therefore, the scientists have not ruled out completely that they could have been infected elsewhere. The researchers, however, seemed “less likely”.

H7 influenza viruses usually spread among birds, the H7N9 sub-group was up to the outbreak of diseases in China never been found in humans. In other cases of avian influenza H5N1 and H7N7 had occurred sporadically to human-to-human transmission, without that this would become an epidemic threat to humanity.

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